In recent years, as a light emitting device, a display device using a self-light emitting element typified by an electro-luminescence (EL) element and the like has been studied and developed instead of a liquid crystal display (LCD) using a liquid crystal element for a pixel. Such a light emitting device has the advantages of high image quality and wide viewing angle because of a light emitting type, and reduced thickness and weight and the like without need of a back light. Thus, the light emitting device is expected to be widely used for a display screen of a mobile phone and a display device.
As for a portable information terminal, a high added value is required with diversification of uses. Recently, a display can be used not only for displaying calls and e-mails but also for displaying landscapes, persons and the like with camera function and browsing Web pages. Further, applications have been enriched. In the future, a portable information terminal having a function to display images of a film, television and the like is expected to be widely used.